Haiti and Venezuela are among 51 countries the United Nations is seeking to help through a $2 billion global humanitarian plan launched this week to respond to the coronavirus.

Globally, there were 566,269 confirmed cases of COVID-19, the disease caused by the flu-like virus, as of Friday, and 26,455 deaths. In Latin America and the Caribbean, where the numbers are growing, there were 81,141 cases and 1,176 deaths as of Friday, according to the Pan American Health Organization.

Even wealthy countries such as the United States, with strong health systems, are buckling under the pressure, and the U.N. says it is increasingly concerned about the virus’ devastating impact as it reaches countries already grappling with humanitarian crises caused by conflicts, natural disasters and climate change. Populations in these nations, already vulnerable, also have to deal with weak public health systems.